Use https URLs.

Author: joto

_libosmium_manual/02_dependencies.md

@@ -195,7 +195,7 @@ returns.
 
 ### GEOS
 
-[GEOS](http://trac.osgeo.org/geos/) is needed if you want to convert OSM
+[GEOS](https://trac.osgeo.org/geos/) is needed if you want to convert OSM
 geometries into GEOS geometries. The GEOS support is deprecated and works only
 until GEOS 3.5. For details see [this
 commit](https://github.com/osmcode/libosmium/commit/3424a7400d70d3b9c5b27b7f704eee2c1725450d).

_libosmium_manual/13_geometries.md

@@ -185,7 +185,7 @@ std::unique_ptr<OGRLineString> line = factory.create_linestring(way);
 
 ### GeoJSON
 
-The [GeoJSON](http://geojson.org/) format describes how to encode geometries
+The [GeoJSON](https://geojson.org/) format describes how to encode geometries
 in JSON.
 
 Libosmium has two different GeoJSON factories. One creates normal

_osmium_tool_manual/09_creating_extracts.md

@@ -21,7 +21,7 @@ If you happen to have a polygon describing Paris, you can use it instead:
 
     osmium extract -p paris-polygon.geojson france.pbf -o paris.pbf
 
-This assumes you have the polygon in [GeoJSON format](http://geojson.org/) in
+This assumes you have the polygon in [GeoJSON format](https://geojson.org/) in
 the file `paris-polygon.geojson`. Osmium also understands the [`POLY`
 format](https://wiki.openstreetmap.org/wiki/Osmosis/Polygon_Filter_File_Format),
 a text-based format popularized first by Osmosis and sometimes used in the OSM